Protected metal article



.lune14, 1949. 'E G, SINGLETQN ETAL 2,472,963

PROTECTED METAL ARTICLE Filed Sept. 4, 1946 ,nes/N16 *gg-T gft-T10 STEEL '/f/////l//fil- INVENToR.

Patented `lune 14, 1949 UNITED STATES PATENT oFFicE y 2,472,963 PROTECTED METAL ARTICLE Fred G. Singleton and Paul W. Jenkins, Pittsburgh, Pa., assignors to H. H. Robertson Company, Pittsburgh, Pa., a corporation of Pennsylvania Application September 4, 1946, Serial No. 694,814

9 Claims. (Cl. 154-45.9)

ored protected metal building sheets possessingdurable weatherproong characteristics, which may be manufactured in an economical and practical manner and which are more suitable and attractive in appearance and more commercially valuable than prior protected metal building sheets and articles of which we are aware.

With this general object in view, and such others as may hereinafter appear, the invention consists in the protected metal article and building sheets, and method of making the same hereinafter described and particularly defined in the claims at the end of this speciiication.

In the drawings illustrating the different features of the invention, Fig. 1 is a vertical section of one form of protected metal building sheet embodying the invention; and Fig. 2 is a similar view of another form of such a sheet embodying the invention.

Fig. 3 is a fragmentary enlarged sectional view of a portion of Fig. 1.

The prior art over which the present invention is an improvement with respect to protected metal building sheets may be illustrated by the United States patents 'to Robertson No. 1,277,755 and to Coffman No. 2,073,334. In the Robertson patent there is disclosed a protected metal building sheet comprising a steel sheet enveloped in an outer weatherprooiing coating of a bituminous or asphaltic composition. In practice this outer weatherproong coating is applied over felt layers saturated with a bituminous impregnant. Protected metal building sheets as thus constructed have been manufactured continuously in large quantities since the issuance of the Robertson patent and have served well in the construction of industrial buildings as roofing and siding materials, and also for many special purposes where corrosive conditions are particularly severe. In practice the sheets are corrugated in order to provide additional rigidity.

For some purposes comparable building sheets produced in accordance with the disclosure of the Coffman patent find general utility, and as therein disclosed the steel sheet is protected by a galvanizing or equivalent coating of fusible metal adhesive, and the brous layers are secured to the steel sheet by the fusible metal adhesive. 'I'he brous layers are preferably impregnated with a 2 bituminous impregnant and in most instances an outer weatherproofing coating of a bituminous nature is applied on top of the impregnated fibrous layers.

'I'he nature of the bituminous materials employed in the felt saturants and in the coatings of the building sheets of Robertson and Coffman has heretofore restricted the possible color combinations and appearance of the building sheets to dark colors such as maroon and black. Experience in the `manufacture of the protected metal building sheets of the character described, following the disclosures of the Robertson and Coilman patents referred to, has demonstrated the efficiency, suitability, and the desirability of the use of asphalt or similar bituminous compositions as an ideal material for use in the protection of the steel sheets from corrosion when the building sheets are exposed to weathering for periods of years. This same experience has emphasized the color limitations of the bituminous coatings and the need for more attractive surface colors than are obtainable with this type of coating. Over the past twenty years or more an exhaustive search has been conducted for a suitable coating material which could be vutilized as a satisfactory outer weatherproong coating in place of the heretofore used bituminous compositionsin order to enable light-colored protected metal sheets to be produced. The primary object of the present invention is the provision of a satisfactory solution to this problem. y

The present invention contemplates the production of protected metal articles and protected metal building sheets of the character specified in which the iibrous layers of the building sheets either of the Robertson patent or the Coffman patent are impregnated with a bituminous composition and coated with a polymerizable resinous coating, the latter then being subjected to treatment to eiect the polymerization of the resinous composition to provide the surfaces of the building sheets with a body of infusible, insoluble, weather-resisting material which may be of any desired color. The invention also contemplates the production of building sheets of the character speciedin which the polymerizable resinous coating is applied as a decorative and attractivev coating over the bituminous outer weatherproofing coatings of the Robertson and Coffman patents.

The desired characteristics of an outer weatherproong coating for a protected metal building sheet of the character specified include the ability to be brought to a state of fluidity as to provide an attractive range of surface colors n for the sheet, and the ability to resist penetra.- tion or solution oi the underlying bituminous materials to the extent that there will be no discoloration of the coating.

The search for a satisfactory 'coating material having characteristics as enumerated has extended over many years and has involved coating of a large number of sample sheets and the weather exposure of the same on the roof, utilizing all materials which from time to time became `available and which seemed to offer any prospect .of solution of the problem. Prior to the present invention, however, no material has been found which was regarded as suitable or capable of ful- .illling the requirements of a satisfactory outer weatherprooflng coating as above outlined. Some materials lacked sufficient durability in the weather, others would not lend themselves to any .practical method of application, others would not adhere to the impregnated brous layers, and .others exhibited a tendency to permit bleeding through of the underlying bituminous materials with the accompanying discoloration of the lightcolored surface.

, A failing common to most of the coating base materials which have been considered in the past has been their lack of resistance to discoloration resulting from bleeding through of the underlying bituminous materials. This bleeding occurred from several general causes. Many of the coating base materials that have been available, and particularly those classes of materials which possess the desired degree ofweather durability, re-

quire the use of strong solvents in substantial. -quantity to render them of suillcient iluidity for application in accordance with commercial practice to the surfaces of the saturated nbrous layers by the fact that the solvents for the coating ma terlal have also been strong solvents for the underlying bituminous coatings and saturants and have tended to leach'out these bituminous materialsV with resulting discoloration of the coating. Another cause of bleeding experienced with coating materials suillciently compatible with .bituminous saturants to adhere to the impregnated brous layers is the mutual solubility of coating base and bituminous materials. This need not be of a very high order to result in pro'- nounced' discoloration of the coating under the iniluence of the sun and the wide changes in temperature experienced by building covering during weather exposure. Whatever the principal cause oi the bleeding, the result has been that up to the development of the present coating material no satisfactorylight-colored weatherproofing material has been 'discovered which was unaffected. i

In accordance withthe `present invention a.

satisfactory materialfor producing a durable light-colored weatherprooiing coating for protected metal building sheets comprises one or more unsaturated polyester resins coniointly polymerized with one or more poiymerizable monomeric solvents. Such a coating may and preferably will be pigmented and filled with suitable materials for producing the color and physical properties desirable for the particular application involved.

Suitable unsaturated polyesters for use in the present invention comprise reaction products produced by heating at least one dihydric alcohol with at least one dicarboxylic acid, or ester-forming derivative thereof, at least one of said dicarboxylic acids being of the type usually referred to as alpha, beta-unsaturated dicarboxylic acids. Dihydric alcohols which may be used comprise ethylene glycol, propylene glycol, the butylene glycols, diethylene glycol, triethylene glycol, the polyethylene glyccls, and unsaturated glycols such as, for example, vinylethylene glycol. Alpha, beta-unsaturated dicarboxylic acid materials which may-be used include maleic anhydride, maleic acid, fumarie acid, citraconic anhydride, citraconic acid and itaconic acid. Although the unsaturated acid may constitute the sole acidic reactant, a wide variation in the properties of the poiymerized resins is obtainable by using varying proportions of other dicarboxylic acid materials such as phthalic acid, phthalic anhydride, and tetrachlorophthalic anhydride, as well as the straight chain aliphatic dicarboxylic acids such as succinic, adipic, azelaic and sebacic acids. The term ester forming dicarboxylic acid materials" as used throughout the claims is in- I tended to include dicarboxylic acids and the anhydrides, esters and acid halides thereof, all of which are ester forming.

While a bi-bifunctional resin is preferred for most purposes, reactants of higher functionality such as glycerol and citric acid may be used, withv the reservation that such polyfunctional reactants must not constitute a suiiiciently large proportion of the total reactants to cause the resin to become insoluble before the molecula weight reaches the desired value.

It is within the scope of the present invention to use monohydric alcohols and/or monocarboxylic acids as modlers in the preparation of the unsaturated polyesters. Unsaturated monofunctional reactants such as allyl and crotyl alcohols and acrylic and crotonic acids may be used. The msaturated polyesters may be of the oil-modiiied ype.

Polyesters of very low molecular weight are not suitable for use in the present invention.

This is probably due to the fact that it is necessary to have a minimum average number of points of unsaturation .per polyester chain in order for the copolymerizing solvent to act eiiectively as a cross-linking agent. Polyesters containing large amounts of unsaturation give useful compositions at lower intrinsic viscosities than those having smaller amounts. For example, polyethylene ma1eate(40%) -adipate- (30%)-phthalate(30%) gave a useful product with half its weight oi' styrene at an intrinsic viscosity of about 0.040, while poly- (diethylene) maleate(10%)phtha1ate(90%) became useful for the purposes of the present invention only at an intrinsic viscosity of about 0.070, and polypropylene ethylene(20%)maleate(3%) sebacate(97%) did not give useful materials even at the very high molecular weight indicated by an intrinsic viscosity of 0.75.

ananas where Ts and Ta represent the time of flow of a dilute acetone solution of the resin and pure acetone, respectively, in an Ostwald viscosimeter, and C is the concentration expressed as grams per 100 cc. of solution. In order to avoid errors due to differences in concentration, all solutions tested were made up to contain one gram per 100 cc. of solution. v

The nomenclature polypropylene -ethylene(%) -maleate(3%) -sebacate(97%) indicates that the polyester was prepared by reacting eighty mole per cent of propylene glycol and twenty mole per cent of ethylene glycol with three mole per cent of maleic anhydride and ninety-seven mole per cent of sebacic acid.

` Copolymerizable solvents suitable for use in the present invention comprise polymerizable unsaturated organic liquids which are compatible with the unsaturated polyesters defined above. Such materials include polymerizable hydrocarbons Intrinsic viscosity= such as styrene, dichlorostyrene, indene, and the coumarone-ndene fraction of coal-tar distillates;

vinyl ketones; vinyl ethers; allyl esters such as ally maleate and allyl phthalate esters of un'- saturated acids such as ethyl acrylate, methyl methacrylate, and ethyl crotonate; and miscellaneous other unsaturated compounds such as acrylonitrile and acrolein. Styrene is the preferred copolymerizing solvent for use in the presing operation, an amount equal to from about one-tenth of one per cent to about ve per cent of any of the well-knownchain-initiating catalysts. Examples of such catalysts which have been found to be particularly adapted to use according to the present invention are aliphatic acyl peroxides such as acetyl peroxide, lauryl peroxide and stearyl peroxide; peroxides ofthe aromatic acid series such as benzoyl peroxide; peroxygen esters such as tertiary butyl perbenzoate; and organic derivatives of hydrogen peroxide such as tertiary butyl hydroperoxide.

In addition to the chain-initiating catalysts described above we prefer to use a small -amount of a. cobalt salt such as, for example, one-tenth of one per cent of cobalt nitrate or naphthenate in order to promote complete polymerization at the surface of the coating Where it is in contact with atmospheric oxygen.

It has been found that when such a resinous composition is applied in liquid form to the bituminous saturated felt layers of the building sheets of either the Robertson or Coffman patents referred to, and the coated sheets subjected to an elevated temperature for a period ofk time .of the requirements with respect to weathering durability, lack of porosity, and the ability to prevent bleeding of the underlying bituminous materials. o

The ability of the present coatings to resist discoloration by the underlying bituminous materials is believed to be due largely to two factors. In the rst place, the unsaturated polyester resins, even in their uncured state, are non-solvents for asphalt, and, in the second place, the solvent is polymerizable and does not remain in the liquid condition. The rate of cure is such that the polyymerizable solvent, e, g., styrene, is polymerized before it has had an opportunity to act to any substantial degree on the bituminous material. The small amount of solvent which penetrates the resin asphalt-saturated felt interface is tied up by subsequent polymerization or reaction of the solvent with the asphalt to produce a bonding layer having bituminous material commingled with the resin. The said layer may be dened as a bonding zone having a resin-bituminous component. The lines A and B of Fig. 3 indicate the zone referred to. .It has been discovered that styrene, for example, willl polymerize in bituminous compositions and that it will react with polynuclear hydrocarbons of the types present in bituminous materials. In any case the practical and very valuable results obtained are independent of any theory.

Illustrating the production of light colored protected metal building sheets of either the Robertson or Coffman type above referred to, the following examples are given although it will be understood that resins may be selected according to the above denition and that various iillers and pigments may be selected from any of the known llers and pigments according to the particular color and other characteristics which it is desired to impart to the outer weatherprooing lm.

Example 1 Grams (2.6 moles) diethylene glycol 275.6 (0.4 mole) maleic anhydride 39.2

(1.6 moles) phthalic anhydride 236.8 (0.3%) p-toluenesulfonic acid 1.6

The reactants were placed in a Claisen ask andwere heated to 200 C. in ve hours and at this temperature for three additional hours. The pressure was then reduced to 0.1 mm. and heating `was continued at 200 C. for two hours, an atmosphere of nitrogen being maintained throughout the reaction. The product, when cool, was a very viscous, almost colorless liquid. The following coating composition was made up:

Above polyester parts 200 Styrene do Titanox B-30 do 30 Chrome oxide green do 30 Benzoyl peroxide do 3 Cobalt nitrate per cent (on resin) 0.1

The polyester was dissolved, with stirring, in the styrene and the pigments and cobalt nitrate were milled into this solution in a ball mill. Just before use the benzoyl peroxide, in the form of a fifty per cent paste in tricresyl phosphate, was stirred in., The resulting coating composition was used to coat a number of 6'? x 12" exposure panels including both the Robertson and Coffman products. In certain of these the resinous thermosetting composition was applied to the asphalt-saturated feltlayers while other sheets had been given the bituminous weatherprooflng ananas 7 coating and the resinous coating was` applied directly over this. These coated sheets were then baked in an oven at different temperatures and for different periods of time. It was found that a cure of ten minutes at about 100 C. gave good results. Temperatures above 130 C. resulted in volatilization4 of the light constituents of the bituminous materials and consequent disruption of the resinous color coat. Temperatures below '10 C. gave good cures but required considerably more time. No discoloration due to bleeding of the bituminous compositions was noted in any case either during application or during cure.

Panels exposed to the weather for four monthsl have shown` no tendency to bleed and accelerated laboratory tests designed to test coatings for bleeding have been completely negative.

Example 2 of the former example. The resulting unsat- `urated polyester was similar to that described above but was more fluid. It produced a more nexible polymerized coating when formulated as described in the previous example. v

Referring now to the drawings, in Fig. l I have illustrated in vertical section a protected metal building sheet of the general type illustrated in the Robertson patent above referred to wherein III represents a steel sheet; I2, i3, the layers of asbestos or other equivalent felt which are secured to the metal sheet by the interposed layers of bituminous material I5, Il. The felt layers may themselves be impregnated with an asphaltic or other bituminous material and the methods of manufacturing the protected metal product as thus far described may and preferably will comprise those now common in practice in the production of the type of protected metal building sheet shown in the Robertson patent above' referred to.

In accordance with the present invention the felt layers impregnated with bituminous material are coated with a polymerizable resinous coating composition of the type above referred to, and after application thereof the resinous layer is subjected to treatment to effect polymerization thereof into a hard infusible resinous layer I6.

In Fig. 2 I have illustrated another form of protected metal sheet of the general type shown in the Cciman patent in which a steel sheet 2l is protected by a galvanized or equivalent coat- 'ing 22 of fusible metal adhesive, and felt layers of asbestos or other felt are secured to the steel sheet by the interposed metal adhesive all as described in the Coffman patent above referred to. The felt layers 24 are impregnated with a bituminous impregnant and the resinous composition applied over the impregnated felt layers. After application of the resinous coating the sheet is subjected to treatment to eifect rapid cure.

From the description thus far it will be observed that the present protected metal articles, and particularly protected metal building sheets either impregnated or coated with the present resinous coating composition lend themselves to the production of light-colored and light-surfaced protected metal articles and sheets. The hard infusible resinous layer or impregnant after curing provides a durable Weather-resisting abrasionresisting weather-proofing coating which will prevent bleeding of the underlying bituminous materials and serves to protect the underlying protective coatings and layers of the complete protected metal article or sheet when the same are exposed to weathering over long periods of time.

The addition of small amounts of cuprous oxide or of cuprous salts, preferably in a finely divided state, such as from,0.01% to 5% or more. so activates the peroxide catalyzed polymerization of the present resinous coatings that they polymerize readily at ordinary temperatures in a time which is easily `adjusted to individual requirements by varying the amount of cuprous compound. This so-called copper effect extends the usefulness of the present invention to those applications where heating subsequent to application of the coating is diilicult or impossible.v

metal sheet, and an outer weather-proofing coating applied over said fibrous material and comprising an insoluble and infusible layer bonded to the bituminous material carried by said fibrous layer, said coating comprising the resinous reaction product formed by reacting a polymerizable liquid monomeric ethylenic group containing solvent for said bituminous material selected from the group consisting of allyl monomers, vinyl monomers and acrylic monomers, with a polyester resin formed by reacting a glycol and an ester-forming, dicarboxylic acid material, said material having at least 10 mol percent of an unsaturated alpha-beta-dicarboxylic acid material, and any remainder being selected from the group consisting of aliphatic saturated dicarboxylic ester-forming materials, aromatic dicarboxylic ester-forming materials, and mixtures thereof, said coating being bonded to said bituminous material along a zone at their interface wherein said coating material and said bituminous material are co-mingled.

2. As a new article of manufacture, a protected metal building sheet comprising a metal sheet, a layer of bituminous-bearing fibrous material covering a surface of the metal sheet, an interposed layer of adhesive bonding the fibrous layer to the metal sheet, and an outer weather-proofing coating applied over said fibrous material and comprising an insoluble and infusible layer bonded to the bituminous material carried by said fibrous layer, said coating comprising the resinous reaction product formed by reacting styrene with a polyester resin formed by reacting a glycol and an ester-forming dicarboxylic acid material, said material .having at least 10 mol percent of an unsaturated alpha-beta-dicarboxylic acid material, and any remainder being selected from the group consisting of aliphatic saturated dicarboxylic ester-forming materials, aromatic dicarboxylic ester-forming materials, and mixtures thereof, said coating being bonded to said bituminous material along a zone at their interface wherein said coating material and said bituminous material are co-mingled.

3. As a new article of manufacture, a protected metal building sheet comprising a metal sheet. a layer of bituminous-bearing fibrous material covering a surface of the metal sheet. an interposed layer of adhesive bonding the fibrous layer to the metal sheet, and an outer weather-proofing coating applied over said fibrous material and comprising an insoluble and infusible layer bonded to the bituminous material carried by said fibrous layer, said coating comprising the resinous reaction product formed by reacting a polymerizable liquid monomeric ethylenic-groupcontaining solvent for said bituminous material selected from the group consisting of styrene, dichlorostyrene, allyl esters including allyl maleate and allyl phthalate, ethyl acrylate and methyl methacrylate, with a polyester resin formed by reacting a glycol and an ester-forming dicarboxylic acid material, said material having at least mol percent of an unsaturated alphabeta-dicarboxylic acid material, and any remainder being selected from the group consisting of aliphatic saturated dicarboxylic ester-forming materials, aromatic dicarboxylic ester-forming materials, and mixtures thereof, said coating being bonded to said bituminous material along a zone at their interface wherein said coating material and said bituminous material are comingled.

4. As a new article of manufacture, a protected metal building sheet comprising a metal sheet, a layer of bituminous-bearing brous material covering a surface of the metal sheet, an interposed layer of adhesive bonding the brous layer to the metal sheet, and an outer weather-proofing coating applied over said fibrous material and comprising an insoluble and infusible layer bonded to the bituminous material carried by said brous layer, said coating comprising the resinous reaction product formed by reacting a polymerizable liquid monomeric ethylenic-groupcontaining solvent for said bituminous material selected from the group consisting of allyl monomers, vinyl monomers and acrylicA monomers,

with a polyester resin formed by reacting a glycoll and an ester-forming dicarboxylic acid material, said material having at least 10 mol percent of an unsaturated alpha-beta-dicarboxylic acid material selected from the group consisting of maleic anhydride, maleic acid, fumarie acid, citraconic anhydride, citraconic acid and itaconic acid, and any remainder being selected from the group consisting of aliphatic saturated dicarboxylic esterforming materials, aromatic dicarboxylic esterforming materials, and mixtures thereof, said coating being bonded to said bituminous material along a zone at their interface wherein said coating material and said bituminous material are co-mingled.

5. As a new article of manufacture, a protected metal building sheet comprising a metal sheet, a layer of bituminous-bearing fibrous material covering a surface of the metal sheet, an interposed layer of adhesive bonding the fibrous layer to the metal sheet, and an outer weather-proofing coating applied over said fibrous material and comprising an insoluble and infusible layer bonded to the bituminous material carried by said fibrous layer, said coating comprising the resinous reaction product formed by reacting styrene with a polyester resin formed by reacting a glycol and an ester-forming dicarboxylic acid material, said material having at least 10 mol percent of an unsaturated alpha-beta-dicarboxylic acid material selected from the group consisting of maleic anhydride, maleic acid, fumarie acid, citraconic anhydride, citraconic acid and itaconic acid and any remainder being selected from the group consisting of aliphatic saturated dicarboxylic ester-forming materials, and mixtures thereof, said coating being bonded to said bituminous material along a zone at their interface wherein said coating material and said bituminous material are co-mingled.

6. As a new article of manufacture, a protected metal building sheet comprising -a metal sheet, a layer of bituminous-bearing brous material covering a surface of the metal sheet, an interposed layer of adhesive bonding the fibrous layer to the metal sheet, and an outer weather-proofing coating applied over said fibrous material and comprising an insoluble and infusible layer bonded to the bituminous material carried by said fibrous layer, said coating comprising the resinous reaction product formed by reacting a polymerizable liquid monomeric ethylenic-group-containing solvent for said bituminous material selected from the group consisting of styrene, dichlorostyrene, allyl esters including allyl maleate and allyl phthalate, ethyl acrylate and methyl methacrylate, with a polyester resin formed by reacting a glycol and an ester-forming dicarboxylic acid material, said material having at least 10 mol percent of an unsaturated alpha-beta-dicarboxylic acid material selected from the group consisting of maleic anhydride, maleic acid, fumarie acid, citraconic anhydride, citraconic acid and itaconic acid, and any remainder being selected from the group consisting of aliphatic saturated dicarboxylic ester-forming materials, aromatic dicarboxylic ester-forming materials, and mixtures thereof, said coating being bonded to said bituminous material along a zone at their interface wherein said coating material and said bituminous material are co-mingled.

7. As a new article of manufacture, a protected metal building sheet comprising a metal sheet, a layer of bituminous-bearing fibrous material covering a surface of the metal sheet, an interposed layer of adhesive bonding the fibrous layer to the metal sheet, and an outer weather-proofing coating applied over said fibrous material and comprising an insoluble and infu'sible layer bonded to the bituminous material carried by said brous layer, said coating comprising the resinous reaction product formed by reacting a polymerizable liquid monomeric ethylenic-group-containing solvent for said bituminous material selected from the group consisting of allyl monomers, vinyl monomers and acrylic monomers, with a polyester resin formed by reacting a glycol and an ester-forming dicarboxylic acid material, said material having at least 10 mol percent of an unsaturated alpha-beta-dicarboxylic acid material, and any remainder -being selected from the group consisting of phthalic acid, rphthalic, anhydride, tetrachlorophthalic anhydride, succinic acid, adipic acid, azelaic acid and sebacic acid, and mixtures thereof, said coating being bonded to said bituminous material along a zone at their interface wherein said coating material and said bituminous material are co-mingled.

8. As a new article of manufacture, a protected metal building sheet comprising a metal sheet, a layer of bituminous-bearing fibrous material covering a surface of the metal sheet, an interposed layer of adhesive 'bonding the fibrous layer to the metal sheet, and an outer weather-proofing coating applied over said fibrous material and comprising an insoluble and infusible layer bonded to the bituminous material carried by said fibrous layer, said coating comprising the resinous reaction product formed by reacting styrene with a polyester resin formed by reacting a glycol and an ester-forming dicarboxylic acid material, said l material having at least 10 mol percent of an unsaturated alpha-beta-dicarboxylic acid material, and any remainder being selected from the group consisting of phthalic acid, phthalic anhydride, tetrachlorophthalic anhydride, succinic acid, adipic acid, azelaic acid and sebacic acid, and mixtures thereof, said coating `being bonded to said bituminous material along a zone at their interface wherein said coating material and said bituminous material are co-mingled.

9. As a new article oi' manufacture, a protected metal building sheet comprising a metal sheet, a layer of bituminous-bearing ilbrous material covering a surface of the metal sheet, an interposed layer of adhesive bonding the fibrous layer to the metal sheet, and an outer weather-proofing coating applied over said brous material and comprising an insoluble and infusible layer bonded to the bituminous material carried by said fibrous layer, said coating comprising the resinous reaction product formed by reacting a polymerizable liquid monomeric ethylenic-group-containing solvent !or said bituminous material selected from the group ,consisting of styrene, dichlorostyrene, ally esters, including allyl maleate and allyl phthalate, ethyl acrylate and methyl methacrylate, with a polyester resin formed by reacting a acuosa glycol and an ester-forming dicarboxylic acid material, said material having at least 10 mol percent of an unsaturated alpha-beta-dicarboxylic acid material, and any remainder being selected from the group consisting of phthalie acid, phthalic anhydride, tetrachlorophthalic anhydride, succinic acid, adipic acid, azelaic acid and sebacic acid,

and mixtures tiereoi, said coating being bonded to said bituminous material along a zone at their interface wherein said coating material and said bituminous material are co-mingled.

FRED G. SINGLETON. PAUL W. JENKINS.

REFERENCES CITED The following referenlces are of record in the le of this patent: A

UNITED STATES PATENTS Great Braam Aug. 24, 1942 l 

